Adjustable drive for doughnut machines



March 30, 1965 E. BELSHAW 3, 75,415

ADJUSTABLE DRIVE FOR DOUGHNUT MACHINES Filed Nov. 13, 1962 3 Sheets-Sheet 1 no D THOMAS E. BELSHIAW INVENTOR.

BY F M M March 30, 1965 Filed Nov. 15, 1962 T. E. BELSHAW ADJUSTABLE DRIVE FOR DOUGHNUT MACHINES 3 Sheets-Sheet 2 'I 19 I m 5 "I I'UHI II N 7 H I 13 I I I I4 A I I} F A rl I ii" jg I ;I I 111' 30 I ll 311" "fig; W 7 ,1?

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BY AMVM ATTORNEYS March 30, 1965 1-. E. BELSHAW ADJUSTABLE DRIVE FOR DOUGHNUT MACHINES 5 Sheets-Sheet 3 Filed Nov. 13, 1962 FIG. 4

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i'HOMAS E. BELSHAW INVENTOR.

ATTORN EYE United States Patent 3,175,415 ADJUSTABLE DRIVE FOR DOUGHNUT MACHINES Thomas E. Belshaw, 1772 22nd Ave. 5., Seattie, Wash. Filed Nov. 13, 1962, Ser. No. 237,250 4 Claims. (Cl. 74-397) The present invention relates generally to a spur gear train with an adjusting mechanism whereby drive shafts at the ends of the train can be rotationally advanced or retarded relative to one another while one is driving the other through the train.

More specifically, the invention aims to provide a simple and economical adjustable drive for doughnut machines of the general type shown in United States Patent No. 1,73 8,033, whereby the size of the doughnut rings can be easily varied at will by manual adjustment while the machine is operating.

With the foregoing and other still more particular objects and advantages in View and which will appear and be understood in the course of the following description and claims, the invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

FIGURE 1 is a fragmentary elevational view of a doughnut machine having its drive mechanism embodying the present invention, the cam part of the drive mechanism being shown in section.

FIG. 2 is an enlarged view taken similarly to FIG. 1 but with the adjusting part of the drive mechanism shown in vertical section and the remainder in fragmentary elevation.

FIG. 3 is a front elevational view with part of the cover of the gear box broken away.

FIG. 4 is a schematic view illustrating the adjustment of the gear train.

FIG. 5 is a fragmentary sectional view taken similarly to FIG. 2 and illustrating a modified adjusting mechanism; and

FIG. 6 is a front fragmentary elevational view of the modified device and corresponding to FIG. 3.

Referring to the drawings it is seen that a spur gear train 111-114 is housed in a gear box 15 onto which a cover 16 is bolted at 19. This box is in turn bolted at 17 to a split case 18 providing a slot for the passage of arms 22-23 which are pivoted in the case 18 on respective pin 24 and carry follower rollers 23. These rollers work on internal tracks provided by a pair of cams 26-27 in turn fixed, respectively, on inner and outer coaxial shafts 3tl-31 which are keyed to gears 11 and 14. Shaft 31) is driven in any suitable manner as by a hand crank or a motor. The arms 22-23, by action of the cams responsive to turning of the shafts 30-31, are reciprocated through travel arcs to drive by their free ends the rods for pistons working at the bottom of a dough hopper 34 in the manner disclosed in the aforesaid Patent No. 1,738,033. The cycles of the pistons are varied relative to one another to vary the size of dough rings formed, and this is accomplished by adjusting the cams circumferentially of their coaxial drive shafts. However, in the mechanism shown in said patent this adjustment must be performed while the pistons are inactive. By the present invention this cam adjustment can be performed while the dough forming machine is in operation, and namely by shifting gear 13 laterally relative to the line of centers between gears 12 and 14 in the controlled manner to be now described.

Gears 11-12 are provided with bushings journaled on respective stub shafts 34-35 which project toward the cover 16 from boss mountings in the opposite Wall of the gear box 15. It will be noted that stub 35 projects beyond the gear 12 and serves as a pivot for a fiat swing arm 36 which extends longitudinally of the box to a semi-cylindrical bulge 16a in the cover 16.

The gear 12 is thicker than gear 11 so as to also mesh with gear 13 while the latter is journaled by a ball bearing unit 37 on a stub shaft 38. This shaft is seated in the swing arm and projects toward the stub shaft 34 in alinement therewith when the swing arm is centered, i.e. has its longitudinal axis parallel to the line of centers of gears 12 and 14. A stop pin 40 projects from the lower end of the swing arm into the bulge 16a to occupy a position between a compression spring 41 and an adjusting screw 42 provided with a knurled head for hand turning. The spring 41 is seated in a cylindrical cage 43 which projects from one end wall of the bulge in alinement with the adjusting screw 42 and the latter is threaded through the other end wall of the bulge and has a retainer ring 44. It will be noted that the stop pin 40 may have a right angle extension 39 serving as a guide for the spring 41. When shafts 30-31 are turned counterclockwise, as viewed from the cover end of the gear box 15, the thrust on the swing arm 36 is clockwise toward the end of the adjusting screw 42 and the spring 41 assures constant contact therewith.

In the example shown schematically in FIG. 4, the gears have the same pitch diameter and the screw 42 has been backed off to advance the swing arm clockwise the angular amount indicated as angle Y. This causes the gear 13 to walk a like amount about the gear 12 so that with reference to the new line of centers between gears 12-13, gear 13 has turned clockwise about its center the angular amount Y that the swing arm was advanced. In addition the original point of contact PC between gears 13-14 has swung an arcuate distance about the center of gear 12 equal to three times the circumferential distance that the original point of contact between gears 12-13 has advanced. This arcuate distance, within the small increments involved of swing of the arm 36 from its center position, can be considered as having occurred along the pitch circle of gear 13, and hence can be translated into an angle 3Y of rotation of gear 13 substantially equal to three times the angle Y. Thus, it is seen that the original point of contact between gears 13-14 has moved clockwise on gear 13 a total angular amount of 4Y. Accordingly as respects gear 14 the original point of contact with gear 13 has moved counterclockwise the angle 4Y to position PC, or in other words, the shaft 31) has advanced relative to shaft 31 an angular amount. equal to substantially four times the angular adjustment of the swing arm 36. In the illustrated example the gears are the same size, but this is not necessary for a practice of the invention. For example, gears 12, 13 and 14 could have a pitch diameter ratio of 1:3:2 in which case the advance of gear 14 would be approximately three times the angular adjustment of the swing arm.

As the gear 13 is swung out of the line of centers of gears 12 and 14, the pitch circles of gears 13-14 of course separate, but since the adjustment of the swing arm is kept within a few degrees, this separation does not materially effect the life of the gear teeth. The point of contact merely moves closer to the tips of the teeth.

In FIGS. 5-6 there is shown a modification in which the function of the swing arm 36 has been assumed by a slide block 136 which operates in a two-part track 137 mounted on the inside face of a modified cover 116. This track extends at right angles with respect to the line of centers of the gears 12 and 14 and movement of the slide block therein is controlled by an adjusting screw 142 and spring 141 as before. A spring cage 143 and 3 guide 139 are also provided, and a stub shaft 138 projects from the slide block to carry the gear 13 on bearing 37. The operation of this modified device is substantially the same as with the swing arm arrangement except that the pitch circle of gear 13 separates from those of both gears 12 and 14. In calculating the multiplication of the lateral shift of the gear 13 with the block 136 from cen tered alinement between gears 12 and 14, the linear shift increment can be assumed to be an are on the pitch diameter of gear 13 in the same manner as the swing arc of the point of contact between gears 1344 relative to the center of gear 12 was so assumed in the prior explanation.

With either embodiment of my invention the shafts 30-31 can be advanced or retarded relative to one another while the doughnut machine is Operating merely by manually turning the adjusting screw 42 or 142.

It will be understood that my invention can also be applied to other types of machines wherein it is desired to rotationally adjust coacting drive shafts relative to one another, and that these shafts do not have to be coaxial and do not require more than three gears in the related gear train when the shafts are in parallel spaced relation.

It is believed that the invention will have been clearly understood from the foregoing description of my now preferred illustrated embodiments. Changes in the details of construction may be resorted to without departing from the spirit of the invention, wherefore it is my intention that no limitations be implied and that the hereto annexed claims be given a scope fully commensurate with the broadest interpretation to which the employed language fairly admits.

What I claim is:

1. In combination, a case, inner and outer concentric drive shafts extending into said case, a spur gear train in said case having at least five gears and having its terminal gears mounted on said drive shafts and having three of said gears consecutively intermeshing on a common line of centers, stub shafts fixed in said case for all of the gears in said train other than said terminal gears and the intermediate of said three gears, a member in said case carrying a journal for said intermediate gear and movable laterally of said line of centers, and adjustable stop means engaging said member for controlling lateral movement of said intermediate gear whereby one of said drive shafts can be selectively advanced relative to the the other.

2. The structure of claim 1 in which said member comprises a swing arm pivot-ally mounted on one of said shafts.

3. The structure of claim 1 in which said member comprises a slide block movably mounted in a track provided by said case.

4. In combination, a case, inner and outer concentric drive shafts extending into said case, a spur gear train of five gears in said case having its first and fifth gears mounted on said drive shafts, having its third gear thick enough to aline with said first and fifth gears, and having its second and fourth gears alined, respectively, with the first and third gears and with the third and fifth gears, stub shafts supported by said case for said second and third gears, a swing arm swingably mounted on the stub shaft for said third gear and supporting a stub shaft for said fourth gear, said second gear intermeshing with said first and third gears and said fourth gear intermeshing with said third and fifth gears, and adjustable stop means engaging said arm for controlling the swing of said fourth gear whereby one of said drive shafts can be advanced relative to the other.

References Cited in the file of this patent UNITED STATES PATENTS 1,492,436 Donahue Apr. 29, 1924 1,713,487 Torrance May 14, 1929 2,536,102 Smith Jan. 2, 1951 

1. IN COMBINATION, A CASE, INNER AND OUTER CONCENTRIC DRIVE SHAFTS EXTENDING INTO SAID CASE, A SPUR GEAR TRAIN IN SAID CASE HAVING AT LEAST FIVE GEARS AND HAVING ITS TERMINAL GEARS MOUNTED ON SAID DRIVE SHAFTS AND HAVING THREE OF SAID GEARS CONSECUTIVELY INTERMESHING ON A COMMON LINE OF CENTERS, STUB SHAFTS FIXED IN SAID CASE FOR ALL OF THE GEARS IN SAID TRAIN OTHER THAN SAID TERMINAL GEARS AND THE INTERMEDIATE OF SAID THREE GEARS, A MEMBER IN SAID CASE CARRYING A JOURNAL FOR SAID INTERMEDIATE GEAR AND MOVABLE LATERALLY OF SAID LINE OF CENTERS, AND ADJUSTABLE STOP MEANS ENGAGING SAID MEMBER FOR CONTROLLING LATERAL MOVEMENT OF SAID INTERMEDIATE GEAR WHEREBY ONE OF SAID DRIVE SHAFTS CAN BE SELECTIVELY ADVANCED RELATIVE TO THE OTHER. 